Metal-insulator transition in stressed Si:B.
Item
-
Title
-
Metal-insulator transition in stressed Si:B.
-
Identifier
-
AAI9820512
-
identifier
-
9820512
-
Creator
-
Bogdanovich, Snezana.
-
Contributor
-
Adviser: Myriam P. Sarachik
-
Date
-
1998
-
Language
-
English
-
Publisher
-
City University of New York.
-
Subject
-
Physics, Condensed Matter | Engineering, Electronics and Electrical
-
Abstract
-
This manuscript contains three chapters: (i) Chapter I contains a review of the theory of metal-insulator transitions in doped semiconductors and a review of the scaling theory of localization and its results. (ii) Chapter II contains experimental data on the magnetoconductance of metallic Si:B. It will be shown that the conductivity data for Si:B with dopant concentrations {dollar}\rm 1.01n\sb{lcub}c{rcub} < n <1.22n\sb{lcub}c{rcub}{dollar} obey universal scaling of the form expected for electron-electron interactions for a large range of magnetic fields and temperatures. The existence of this scaling implies that the metal-insulator transition is dominated by interactions. Detailed analysis of the data show that the localization, spin-orbit and spin-flip interactions do not play an important role in transport processes in this material. (iii) Chapter III contains experimental data on the stress-tuned metal-insulator transition in Si:B. Uniaxial stress drives a metallic sample into the insulating phase by decreasing the impurity wavefunction overlap and increasing the value of the critical concentration {dollar}\rm n\sb{lcub}c{rcub}.{dollar} The conductivity obeys dynamical scaling as a function of temperature and stress near the critical point in both metallic and insulating phases. Important findings are: (a) The approach to the transition by variation of stress and variation of the dopant concentration are very different. (b) The critical conductivity has a {dollar}\rm T\sp{lcub}1/2{rcub}{dollar} behavior similar to the conductivity outside the critical region due to electron-electron interactions. (c) The conductivity of the insulator obeys Efros-Shklovskii hopping due to electron-electron interactions {dollar}\rm\sigma\sim T\sp{lcub}1/2{rcub}exp\lbrack {lcub}-{rcub}\rm (T\sb0/T)\sp{lcub}1/2{rcub}\rbrack {dollar} with a temperature dependent prefactor {dollar}\rm\propto\ T\sp{lcub}1/2{rcub}.{dollar}.
-
Type
-
dissertation
-
Source
-
PQT Legacy CUNY.xlsx
-
degree
-
Ph.D.
